The ermine kills its prey with a bite to the back of the prey's neck. Rodents and rabbits are the ermine's main diet. It will also kill and eat other mammals bigger than itself. Sometimes ermines eat birds, eggs, fish and insects. At the beginning of winter, the ermine loses its dark fur and grows a pure white coat. This white winter pelt is prized by the fur trade. Ermine are found in Europe, Asia, the northern U.S.A., and Greenland.